Endocrine Abstracts

We have previously shown that adults with partial GHD have increased total body and truncal fat mass, an adverse lipid profile, and insulin resistance. In this study we have gone on to analyse suggogate markers of vascular risk and carotid IMT. We defined GH status using the combination of two stimulation tests, the ITT and arginine stimulation test, in to patients with severe GHD (pGH<3 ng/ml, n=30) or GH insufficiency (pGH 3–7 ng/ml, n=24). Thirty age and gender matched control subjects were also studied.

There were no differences in age between the GHD, GHI, and control subjects (30.9 vs 31.5 vs 34.2 yrs). IGF-I levels were significantly lower in the GHD adults (208±115 ng/ml) than the GHI or control subjects (P=0.006, P<0.001 respectively), and were lower in the GHI subjects (295±104 ng/ml) compared with control subjects (373±123 ng/ml, P=0.016). Lipoprotein (a) levels were 19.4±20.4, 23.8±25.5, & 15.7±20.6 ng/ml in GHD, GHI, and control subjects respectively (P=ns). Fibrinogen levels (201±138, 205±135, & 205±104 ng/ml respectively) were not significantly different between the groups. PAI-I levels were significantly higher in the GHD and GHI adults compared with controls (72.4±31.5 vs 51.3±34.3 ng/ml, P=0.02; & 75.8±26.1 vs 51.3±34.3 mmol/l, P=0.01), with no difference between GHD and GHI subjects. C-reactive protein (CRP) was not significantly different between the three groups (9.7±13.6 vs 5.5±3.3 vs 4.6±2.6 ng/ml respectively). Carotid IMT assessed by high resolution USS was 0.586±0.14, 0.578±0.13, and 0.503±0.08 mm in the GHD, GHI, and control subjects. Carotid IMT was significantly greater in both patient groups compared with controls (P=0.01 & P=0.02).

The results show GHI adults, in addition to previous data showing these patients to have excess truncal fat mass, an adverse lipid profile and insulin resistance, have elevated PAI-I levels. PAI-I is an independent risk factor for vascular disease. A direct measure of vascular disease, carotid IMT, was also increased in GHI adults. These data collectively suggest GHI adults are at risk of excess vascular disease.